The penalty for using a mobile phone while driving could be doubled under proposals being examined by the Government as part of a safety drive, Transport Secretary Patrick McLoughlin said.

Metropolitan Police Commissioner Sir Bernard Hogan-Howe has called for offenders to be handed six points on their licence rather than the present three, meaning a ban from getting behind the wheel if caught twice in three years.

Mr McLoughlin said it was an "interesting suggestion" that he was considering in an effort to end the "appalling" number of people killed and seriously injured in accidents where a phone was being used in the hand.

"The amounts of casualties there have been are absolutely appalling and the person who is using their phone doesn't realise the damage or the danger," he told journalists at a Westminster lunch.

"In 2011 driving while using a mobile phone was recorded as a contributory factor on some 23 fatalities and 74 serious injuries. We have got to change this and we have got to get that message across.

"Sir Bernard Hogan-Howe has called for six penalty points for the use of a mobile phone. It is an interesting suggestion.

"It is one that I would want to look at. There could be some difficulties about it but I think we have got to get the message across to people about safety.

"We have been very lucky in this country in seeing, year on year, the number of road deaths and casualties actually falling.

"But one death is one too many and we need to look at those and see where we are going."

The Scotland Yard chief spoke out in March after figures showed the first increase in deaths and injuries on the capital's roads for two decades.

It has been illegal since December 2003 to use a mobile phone held in the hand while driving.

Mr McLoughlin criticised Labour for considering allowing the public sector to compete with private firms to run railway services, insisting privatisation had brought huge benefits and should not be rolled back.

The Opposition is yet to announce its policy but, asked about the prospect of opening franchise bids to the public sector, he asked who would pay for the public bids to be drawn up and what influence ministers could face from unions.

"Can you imagine it? A state-backed body competing with the private sector with the telephone ringing between the RMT or Aslef as to who should win that competition," he said.

"Is the private sector going to continue to take those calls?"

Asked if a Yes vote to Scottish independence in September's referendum would end the prospect of the HS2 high-speed rail link being extended across the border, he said: "I think it is very important for HS2 to serve the whole country and I think we are far better as one rather than trying to split the country.

"I want to see HS2 services going to Scotland and I am working on those proposals at the moment. I am not anticipating us getting to the situation of the United Kingdom breaking up because I believe the people of Scotland will vote the right way in the referendum."

He joked about seeking ways to reduce the UK's population of great-crested newts whose habitats, he said, were proving an obstacle to many transport schemes including the high-speed rail line.

"I'm tempted to see if I can order, through the Department of Transport, 50 herons, because if a heron eats a great crested newt it's okay, but if we try and move it, God are we in trouble."

Professor Stephen Glaister, director of the RAC Foundation, said the problem was not with penalties but with enforcement.

"Our own research shows how dangerous using a mobile at the wheel can be," he said.

"Texting while driving impairs reactions more than being at the drink-drive limit or high on cannabis.

"However the large number of motorists still using phones at the wheel is less about the size of penalties and more about the chance of being caught.

"The Department for Transport's own figures show that on two previous occasions when this law was tightened and fines increased the number of people offending initially dropped but then rapidly rose again.

"The conclusion must be that drivers simply don't think they are going to be caught."